Low-resistance vapor electric device.



P. C. HEWITT. LOW RESISTANCE VAPOR ELECTRIC DEVICE.

APPLICATION -FILED AUG-14. I907.

Patented Oct. 12, 1915.

2 SHEETSSHEET I.

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MW-tame. co

P. C. HEWJTT. LOW RESISTANCE VAPOR ELECTRIC DEVICE.

APPLlCATION FILED AUG.14| 1907. 1 156 2271 Patented Oct. 12, 1915.

2 SHEETSSHEET 2.

- the surface of the negative electrode.

UNITED STATES PATENT o FIoE.

PETER COOPER HEWITT, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS,TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A.CORPORATION OF NEW JERSEY.

- IiOW-ZRIIEISISTAN(3E VAPOR ELECTRIC DEVICE.

Specification of Letters Iatent.

Patented Oct. 12, 1915.

Application filed August 14, 1907. Serial No. 388,465.

To all whom it may concern:

Be it known that I, PETER COOPER HEWITT, a citizen of the United States,and resident of New York, county of New York, State of New York, haveinvented certain new and useful Improvements in Low-Resistance VaporElectric Devices, of which the following is a specification.

My invention relates to means and methods of controlling variousreactions at and between two electrodes separated by a gas or vapor.

In a gas or vapor apparatus haying a negative electrode or cathode, anda positive electrode or anode, or several of either, the

normal drop in potential between a positive terminal and a cathode maybe, when the cathode or negative electrode resistance is electrodes andparticularly in con-trolled and inclosed devices and have determinedwithin limits the respective localities and estimated the relativevalues of their various resistances. The reactions referred topresenting resistance may be most conveniently considered for the'purposes of this invention in the following subdivisions: 1, those at oraround the positive electrode; 2, those in the positive column or gas orvaporpath between the positive electrode and the negative dark space; 3,the reactions at the point of transition between the positive column andthe negative dark space; and 4, the reactions in the dark space andthosenat relations or proportions of these fourseats of sources ofpotential drop in volts may,

for the purposes of this description, be roughly considered as follows:at 1, as 5 to 7; at 2, as lto 2; at 3, as 3 to 5; at 4, as 4 to 6. Thesereactions are modified by gas density and the zone of the reactions isenlarged by increased rarefaction of the gas or vapor, particularly thezone of the reactions at 4. They are affected and varied by gasimpurities and other features. As accurate measurements are difficult"to obtain separately, due allowance must be made, but the valuesmentioned serve to give a falr idea for the purposes of thisdescript1on. Cons1der1ng these, seats'of potential drop, I find that Ican modify, if not entlrely el minate, some of the reactions therebyreduclng the normal drop in potential between electrodes 1n devices ofthis character to a limit considerably lower than has heretofore beenused in commercial practice. In certain uses for which vapor devices areserviceable, .such, for example, as the well known converters orrectifiers, it is impor-- tant that the internal heating effect, that isto say,the heat generated by the device in normal operation, should beas small as possible. If, for example, the total drop of potentlal canbe materially modified or reduced, the same device will be able to passmore current for the same amount of heat generated or it will pass anequal current with a considerably smaller development of heatan'important feature in a device where-its temperature governs the density.A given device having its normal capacity limited-by the ability toradiate -heat can be utilizedto pass a larger current when the potentialdrop between the terminals is small than it can when the potential dropover it is comparatively large.

I have'found' that by locating the positive electrode or anode in closeproximity to the negative electrode or cathode, so that the reactions atone terminal come under the zone of influence of the other, the totalpotential drop in the vapor device under similar conditions may bereduced to from 7 to 8 volts and in some caseseven lower. My experiencehas led me to believethat there exists acritical region, limitedprobably by the dark space adjacent to the negative electrode, withinwhich region the actions at or around the positive electrode, those ofthe positive column, and those at the joint between the positive columnand the dark space, are wholly or partially suppressed, and it is thepurpose of this application to render this discoveryserviceable in thearts, and it is thought that the disclosure made herein should be asuflicient guide for those wishing to utilize the principles involved inmy invention. I have already stated that pears further that in order tosecure the best results electrodes should be placed within this criticalregion in such relation to each other as to cause the reactions at oneelectrode, a negative, to affect those of the other,

a positive. Under these conditions, the posi- I tive and negativereactions may be said to occupy substantially the same space or bewithin the same zone of influence. Assuming that the electrodes aresuitably located within the dark space, the distance of physicalseparation between said electrodes may be varied without seriouslyaffecting the results, by varying the quality of perfection of thevacuum in the container within which the electrodes are inclosed. Themore perfect the vacuum. the more widely the electrodes may be separatedwithout altering the results. Or, looked at in another Way, thecl1rrent-carrying-capacity of the vapor device, assuming a fixedrelation between the electrodes within the critical region, may beincreased by a decrease of density therein. Thiscurrent-carrying-capacity, in its turn, is increased by an increase ofcurrent for the same density, since the increase of current may ofitself extend the-darkspace.

\Vhile I am not prepared to state the exact cause of the actiondescribed herein, as it is probably very complex, and while I am notable to state the exact degree in which the various resistances aremodified 01' reduced, yet from my investigations it appears as if. underthe conditions recited, reactions noted above as 1 and 2 are verymaterially lessened, if not substantially suppressed, while thereactions which take place at 3 appear to be modified toa very greatextent.

This discovery is useful in connection with gas or vapor gaps, vaporconverters, interrupters, electric valves, and other devices, and may beadopted advantageously in connection with the electrodes for akeep-alive circuit.

The apparatus in which my discovery may be embodied may take variousforms and l have only thought it necessary to illustrate a few suchforms in the following figures of drawing, which represent three severalways of embodying my discovery in useful types of apparatus, togetherwith a detail in Figure 4 of a modification.

Referring to the drawings, Fig. 1 shows a bulb, 1, having. a negativeelectrode or cathode, 2, of mercury, or other self-reconstructingmaterial, and having two positive electrodes or anodes, 3 and 4, ofsolid material, such as iron. The circuit wires, 5 and 6, connected withthe leads, 7 and 8, of the respective positive electrodes 3 and 4, passthrough reentrant portions, 9 and 10, of the glass bulb and the leadsthemselves beyond that point are surrounded by glass protecting sleeves,11 and 12, to points to be approached as much as possible to thenegative. The positive electrodes 3 and 4t are connected, respectively,to the terminals of a coil, 34, constituting the secondary of a primary,33, connected with a source of alternating current. The transformer thusindicated is simply chosen for purposes of illustration and any suitablesource of alternating current may be substituted to suit differentconditions. An intermediate point of the secondary 34 is connected tothe negative electrode 2 as shown. These connections are now well knownas those of a vapor converter or rectifier and they are simplyillustrated for the sake of clearness. With the positive electrodesplaced as shown in Fig. 1 in close proximity to the negative electrode2, the resultant converter or rectifier may be operated withoutexcessive heating with comparatively large currents, the drop ofpotential between the positive and negative electrodes being reducedconsiderably below what is normal in the case of a wide separation ofthe said electrodes, or where the electrodes are not subject to mutualin-. fluence. I

In Fig. 2 it have shown a device which is adapted to be used as anelectric valve and particularly adapted for high vibratory currentssuch, for example, as may be used in wireless transmission. Here theactive positive electrode is shown at 14 in the form of a disk of ironor other solid conducting ma-' nected to a lead, 19. running to thenegative electrode 9.. In the circuit of the source 18 I introduce avariable resistance, 20, and an inductance, 21, which may also bevariable. as shown. While the apparatus is in opera tion, the circuit ofthe source 18 is kept closed and current always passes through thecircuit. any suitable means for starting the flow of current beingadopted. By reason of the close proximity of the positive electrode 15to the negative electrode 2, the resistance of the described circuitinside the vapor device 1 is comparatively small. ()ne lead of a sourceof variable current is connected to the lead 40, while the otherterminal, if one is used, is connected either at 16 or 19. In order toavail of the valveaction of the device it is only necessary to connect adirect current translating device in parallel circuit between these twoleads having inductance, 2-1, in its circuit. shown the positiveelectrode 15 as being connected beyond its point of union with thecircuit of the source 18 to ground at G. To the ground circuit I haveconnected a circuit 22 containing a direct current translating device,23, and an inductance, 24. To the circuit 22 is connected by a.conductor 25 the main positive electrode 1-1. The conductor 22 may becontinued in the form of an antenna, 26, subject to the influence ofvibratory currents such as are used in wireless telegraphy or of anykind of power. The inductance 21 may be omitted provided the inductanceof the translating device 23 is sufficient in itself without theadditional aid. The translating device 23 may be an ordinary telephonereceiver, a direct current motor, or other suitable apparatus adapted totranslate the energy received.

In Fig. 3 I show a device somewhat similar to that illustrated in Fig.2, but more especially adapted for the rectification of simplealternating currents' The positive electrode which in the previousfigure was called the main positive electrode is here dispensed with andthe electrodes 15 and 2 are connected to the terminals of an alternatingcurrent source shown at 27 and 28 as being, respectively, the primaryand secondary of a transformer. In this case I show a starting band 29,connected by a conductor, 30, with one side' of the circuit to assist instarting operation which starting operation, may, however, beaccomplished by any method that may be preferred. In this instance theelectrode 15 becomes the main positive electrode of the device and owingto the well known action of apparatus of this kind current will onlypass in one direction through the device, the waves of opposite polaritybeing suppressed by the action of negative electrode resistance at thepositive electrode. Accordingly, the circuit, 31, will be traversed by apulsating current of uniform direction, but not by an alternatingcurrent. At 32 is shown a translating de vice for utilizing therectified current. In

- this case also the electrode 15 is placed in very close proximity tothe negative electrode 2 and the normal potential drop over the deviceis thereby greatly reduced.

In the figures of the drawingthe lead to the negative electrode isrepresented as being connected withv a piece, 35, of platinum,

I have iridium, iron, or other suitable conducting material,constituting a point which projects slightly above the surface of themercury illustrated in Fig. 1 and in some cases may be found moredesirable. The two positive electrodes 3 and 4 are arranged in thisinstance, .respectively, on the inside and outside of a vessel, 39, ofglass or other suit able material, the said "vessel being generally cupshaped and having a central reentrant open boss or cylinder, 41. Theelectrode 3, for example, is in the form of a ring surrounding the bossand connected through the vessel to the lead wire 5. The electrode 4stands above the opening in the base of the cup, or, say, at the upperend of the boss, 41, and is connected to the lead 6. With th1sarrangement both positive electrodes may be brought into suflicientlyclose proximity to the negative electrode 2, while being amply protectedfrom short-circuiting by the structure shown and described.

I claim as my invention:

1. A vapor electric apparatus comprising a l-exhausted container,positive and nega- 1.00 tive electrodes therein, the positive electrodebeing located and supported within the region in which the negativeelectrode component of'the totalfall of potential occurs.

2. A vapor electric apparatus comprising 105 an exhausted container,positive and negative electrodes therein, said container being shaped tooffer cooling surface for said apparatus, the positive electrodes beinglocated and supported within the dark space in the 110 neighborhood ofthe negative electrode.

3. A vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, the said positive and negativeelectrodes being separated by less 115 than a critical distance, thelimit of which is the dark space adjacent to the negative electrode,whereby the total fall of potential between the terminals of theapparatus is materially less than 14: volts.

4:. In a vapor electric device, an exhausted container, a negativeelectrode therein of volatile self-reconstructing material, and apositive electrode therein of solid material, the said positiveelectrode being located 115 within a critical region limited by thenegative electrode and the region'of approximately the same potentialadjacent to said negative electrode.

5. In a vapor electric apparatus compris- 130 ing an exhaustedcontainer, a cathode with Signed at New York, in the county of New a.dark space adjacent thereto, an anode 10- York, and State of New York,this 7th day cated in said dark space in fixed relation to of August, A.D. 1907.

said cathode, an anode stem connected to PETER COOPER HEWITT. said anodeand an lnsulatmg covering for \Vitnesses:

said'stem, said covering being integral with \VM. H. CAPEL,

said container. GEORGE H. STOCKBRIDGE.

